US3886456A - Wired broadcasting systems providing telephone communication - Google Patents
Wired broadcasting systems providing telephone communication Download PDFInfo
- Publication number
- US3886456A US3886456A US310118A US31011872A US3886456A US 3886456 A US3886456 A US 3886456A US 310118 A US310118 A US 310118A US 31011872 A US31011872 A US 31011872A US 3886456 A US3886456 A US 3886456A
- Authority
- US
- United States
- Prior art keywords
- programme
- subscriber
- exchange
- high frequency
- conductors
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
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Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N7/00—Television systems
- H04N7/16—Analogue secrecy systems; Analogue subscription systems
- H04N7/173—Analogue secrecy systems; Analogue subscription systems with two-way working, e.g. subscriber sending a programme selection signal
- H04N7/17345—Control of the passage of the selected programme
Definitions
- H04m 11/08 is associated i h an in r i ial p ir of con ctors
- Field of Search 179/2 TV, 2 R, 2 DP 2 E, suitable for low frequency signals. Provision is made 179/2 C, 2 AS, 1 B; 325/31, 303; 178/1)[(] 13 for connecting conventional telephone instruments at the subscriber station which is linked to a telephone [56] Refer nces Cit d exchange through a pair of the said conductors.
- the present invention relates to wired broadcasting systems by which a number of television or other programmes may be transmitted through a distribution network to a plurality of subscribers who are able to select desired programmes.
- Such a system is extremely versatile and may be used not only for the transmission of vision signals from the programme exchanges to the individual subscribers, but a wide range of other facilities can be provided.
- the subscriber will also be a telephone subscriber, and it has been realised that telephone service to the subscriber may be provided by the intersticial conductors of the wired broadcasting system.
- the present invention is concerned with methods by which telephone service may be combined with a wired broadcasting system of the character referred to without involving an independent wire for the telephone service.
- the equipment incorporates means to avoid interference between selection signals initiated by the subscriber for selecting some particular service through the broadcasting network and the telephone network.
- the invention provides a wired broadcasting system in which each of a plurality of subscribers is connected to a programme exchange through the intermediary of a twisted pair of high frequency conductors suitable for the transmission of high frequency television signals having associated therewith intersticial audio frequency conductors suitable for the transmission of audio frequency signals and in which means are provided whereby a telephone instrument at the subscribers premises may be connected to a telephone exchange through a pair of said wired broadcasting conductors.
- the invention also provides a wired broadcasting system in which the audio frequency conductors are employed to connect the telephone instrument to a telephone exchange and signalling and control of the television programme selector switch at the programme exchange is effected through the high frequency conductors in conjunction with a return path formed be a cable screen about the conductors between the programme exchange and the subscriber.
- the invention provides a wired broadcasting system in which the audio frequency conductors are employed to connect the telephone instrument to a telephone exchange and signalling and control of the television programme selector switch at the programme exchange is effected by polarised direct current signalling through the high frequency pair in conjunction with polarised responsive devices at the programme exchange.
- the invention provides a wired broadcasting system in which the audio frequency conductors are employed selectively to connect the telephone instrument to a telephone exchange and for the signalling and control of the subscribers television programme selector switch at the programme exchange, operation of the subscribers selector switch resulting in disconnection of the telephone circuit during the period required for television programme selection.
- FIGS. 1 and 2 show respectively the subscribers equipment and the programme exchange equipment according to a first embodiment of the invention.
- FIGS. 3 and 4 show similarly the features of a second embodiment of the invention.
- FIGS. 5 and 6 show similarly the features of a third embodiment of the invention.
- FIGS. 1, 3 and 5 the essential parts of the subscribers equipment are shown diagrammatically the input from the supply cable being shown as a drop wire 10 with the four connecting leads 12 for one subscriber, one pair 13 comprising the vision circuit feeding an inverter 14 providing a VHF output to the input terminal of the television receiver.
- the subscribers drop wire forms part of a cable having a cable sheath 15 which is used for the return path for signalling by the application ofa direct current path to either of the vision wires 1 or 2.
- the subscriber's control switch is shown as a conventional telephone dial 16 the springset 17 of which is adapted to apply a direct current path during subscriber selection to the vision line 1 leading to the drop wire 10.
- a reset switch 18 is also shown which applies a direct current path to the vision line 2 providing for signalling to the programme exchange equipment.
- the other two wires of the subscribers drop wire 19 feed cable which are the intersticial conductors are connected at the subscribers equipment to the normal telephone handset 20 as indicated.
- the audio circuits are fed through a hybrid transformer 21, the audio lines being muted by the off-normal muting contacts 22 of the subscriber's dial selector while the springset 17 is adapted to transmit direct current signalling pulses into the vision line I the return path for which is provided through the cable sheath 15.
- the subscriber's reset switch 18 is adapted to supply a direct current connection between the cable sheath and the line 2. It will be seen that the intersticial pair of conductors 19 in the feed cable are connected at all times to the telephone handset 20 so that the telephone is available whenever required.
- FIG. 2 shows the circuit at the programme exchange. It will be noted that one pair 19, the telephone pair, of the subscribers lines is connected through a suppres' sion filter 24 to the telephone exchange network (not shown) while the vision pair 13 is connected through video and audio balancing transformers 25, 26 to the moving member of the selector switch 28 so that a pro gramme picked up from any of the programme trunks 29 may be transmitted to the subscriber in accordance with signals originated by him over the control pair 13.
- These signals are extracted by the balancing trans former systems and fed in the case of the drive signals passed through line 1 of the subscribers cable, to operate the driving magnet DM of the rotary selector switch which causes switch 28 to switch from trunk to trunk. Operation of the reset switch at the subscribers station on the other hand operates the magnet RS which releases the subscribers switch so that it returns to a normal or datum position at a preselected trunk.
- FIGS. 3 and 4 illustrate a system which has a number of features common to FIGS. 1 and 2 and thus carries similar reference characters with primes showing elements in modified form, but signalling is performed by selective polarity signalling between the two vision lines I and 2 thus avoiding the need for a return path through a cable sheath, the selective signalling conditions operating different relays R1 and R2 at the programme exchange (FIG. 4).
- AC power is taken from an input power supply to operate a DC power pack 30 which is adapted to transmit dial signals of one polarity between the lines 1 and 2 or of the other polarity for the reset pulse. Additional off-normal contacts are required to provide the contact pair 22' at the subscriber's selector dial and similarly additional contacts are required for the reset switch 18.
- signals received from the vision lines 1 and 2 are ex tracted by the video and audio balancing transformers 25 and 26 and operate one of two relays R1 or R2 associated with diodes D1 and D2 according to the signal polarity transmitted by the subscriber.
- the relay R2 transmits dialling pulses to the drive magnet DM and the relay R1 transmits the reset pulse to the reset magnet RS.
- the intersticial pairs of conductors 19 are connected to the telephone network through an interference suppression filter 24 as in the case of FIG. 2.
- FIGS. 5 and 6 show an arrangement in which the intersticial control conductors 19 of the feed cable are shared between the telephone service and control signals for operating the subscribers switch at the programme exchange.
- the telephone handset 20 and the control dial contacts 16 of the sub scribers selector equipment are selectively connected to the control lines 19 through a control switch S which is operated by the subscriber when he wishes to perform programme selection by means of his selector diaE. Operation of the switch for this purpose disconnects the telephone handset while programme selection is in process and mutes the audio feed to the subscribers television receiver while the telephone is in use. It will be noted that operation of the switch S to its alternative programme selection position results in applying DC conditions across the vision lines 1 and 2.
- switch S in the unoperated position of switch S shown in FIG. 5, one telephone wire is connected to one wire of control pair 19 and this is disconnected upon operation of switch S.
- switch 5 shorts out the condenser connected in the audio output transformer circuit to apply the DC condition across vision lines I and 2 to thereby ground and energize relay R3 (FIG. 6).
- relay R3 In normal contacts 22 mute the audio in the same manner as in FIG. 1.
- the operation of switch S also serves to place DC ground upon one of the control conductors 19 so that switch 16" can apply the DC pulses thereto in response to operation of the dial.
- this operation results in energisation of a control relay R3 having changeover contacts R31 and R32 which in the normal position shown connect the control pair 19 of the subscriber's cable 10 to the telephone network (not shown). Conversely on operation of the relay R3 the contacts R31 and R32 connect the control lines to the driving magnet DM or the reset magnet RS of the selector switch 28. It will be appreciated that with this circuit the telephone is disconnected for a short period during programme selection or resetting by the subscriber.
- a wired broadcasting system in which each of a plurality of subscribers is connected to a programme exchange through the intermediary of a cable with a twisted pair of high frequency conductors suitable for the transmission of high frequency television signals and having associated therewith a twisted pair of intersticial audio frequency conductors suitable for the transmission of audio frequency signals and in which means are provided including a central programme exchange with programme selection means and a telephone exchange, a telephone instrument at the subscribers premises connected to said telephone exchange through said pair of intersticial conductors, means at said subscribers premises for sending DC signals over at least one of the high frequency conductors to operate said programme selection means, a television programme selector switch, means effecting signalling and control of the television programme selector switch at the programme exchange through the high frequency conductors in conjunction with a return path formed by a cable screen about the conductors between the programme exchange and the subscriber, a dial selector having off normal contacts connected to mute the audio, means to introduce direct current signalling pulses into one of the high frequency conductors, and means providing that audio frequency
- a wired broadcasting system as claimed in claim 1 including a subscriber's control switch with a dial selector and springset, and means including the springset adapted to apply a direct current path between one of the high frequency conductors and the cable screen to effect programme selection.
- a wired broadcasting system in which each of a plurality of subscribers is connected to a programme exchange through the intermediary of a cable with a twisted pair of high frequency conductors suitable for the transmission of high frequency television signals and having associated therewith a twisted pair of intersticial audio frequency conductors suitable for the transmission of audio frequency signals and in which means are provided including a central programme exchange with programme selection means and a telephone exchange, a telephone instrument at the subscribers premises connected to said telephone exchange through said pair of intersticial conductors, and means at said subscribers premises for sending DC signals over at least one of the high frequency conductors to operate said programme selection means having a television programme selector switch and including means effecting signalling and control of the television programme selector switch at the programme exchange by polarised direct current signalling through the high frequency pair and polarised responsive devices at the programme exchange responding to said polarised direct current to operate said selector switch, wherein the polarised responsive devices comprise two relays, one being arranged to effect selection of television programmes by means of the subscriber s television programme selector switch
- polarised relays are formed by non polarised relays each having associated therewith a diode.
- a wired broadcasting system in which each of a plurality of subscribers is connected to a programme exchange through the intermediary of a cable with a twisted pair of high frequency conductors suitable for the transmission of high frequency television signals and having associated therewith a twisted pair of intersticial audio frequency conductors suitable for the transmission of audio frequency signals and in which means are provided including a central programme exchange with programme selection means and a telephone exchange, a telephone instrument at the subscribers premises connected to said telephone ex change through said pair of intersticial conductors, and means at said subscribers premises for sending DC signals over at least one of the high frequency conductors to operate said programme selection means having a subscribers television programme selector switch and including means effecting signalling and control of the subscriber's television programme selector switch at the programme exchange, and means coupled with the subscribers selector switch disconnecting the telephone circuit during the period required for television programme selection.
Landscapes
- Engineering & Computer Science (AREA)
- Multimedia (AREA)
- Signal Processing (AREA)
- Telephonic Communication Services (AREA)
- Two-Way Televisions, Distribution Of Moving Picture Or The Like (AREA)
- Shielding Devices Or Components To Electric Or Magnetic Fields (AREA)
- Interface Circuits In Exchanges (AREA)
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GB5629971A GB1414127A (en) | 1971-12-03 | 1971-12-03 | Wired broadcasting systems |
Publications (1)
Publication Number | Publication Date |
---|---|
US3886456A true US3886456A (en) | 1975-05-27 |
Family
ID=10476280
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US310118A Expired - Lifetime US3886456A (en) | 1971-12-03 | 1972-11-28 | Wired broadcasting systems providing telephone communication |
Country Status (15)
Country | Link |
---|---|
US (1) | US3886456A (sv) |
JP (1) | JPS4865831A (sv) |
BE (1) | BE792215A (sv) |
CA (1) | CA965526A (sv) |
CH (1) | CH549919A (sv) |
DE (2) | DE2258416C3 (sv) |
ES (1) | ES409180A1 (sv) |
FR (1) | FR2162236B1 (sv) |
GB (1) | GB1414127A (sv) |
IL (1) | IL40843A (sv) |
IT (1) | IT973762B (sv) |
MT (1) | MTP731B (sv) |
NL (1) | NL7216232A (sv) |
SE (1) | SE383817B (sv) |
ZA (1) | ZA728071B (sv) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5539635A (en) * | 1994-07-19 | 1996-07-23 | Larson, Jr.; Ernest J. | Radio station program identifier and distribution system |
Families Citing this family (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4386365A (en) * | 1979-06-19 | 1983-05-31 | Communications Patents Limited | Combined wired broadcasting and viewphone system |
CA1284211C (en) * | 1985-04-29 | 1991-05-14 | Terrence Henry Pocock | Cable television system selectively distributing pre-recorder video and audio messages |
GB9201996D0 (en) * | 1992-01-30 | 1992-03-18 | Millicom Satellite Tv Services | Communication systems |
Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3244809A (en) * | 1961-03-01 | 1966-04-05 | Pye Ltd | Signal distribution systems |
US3277243A (en) * | 1962-12-19 | 1966-10-04 | Burroughs Corp | Telephone adapter |
US3350647A (en) * | 1962-10-25 | 1967-10-31 | Communications Patents Ltd | Wired broadcasting systems and communication cables therefor |
US3587053A (en) * | 1968-06-10 | 1971-06-22 | Bell Telephone Labor Inc | Audio visual information processing and communication system |
US3691295A (en) * | 1970-03-31 | 1972-09-12 | Ibm | Two-way communication system for video and digital data |
Family Cites Families (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
FR1536780A (fr) * | Communications Patents Ltd | Dispositifs et appareils de télédiffusion par fils | ||
DE884050C (de) | 1937-08-08 | 1953-07-23 | Siemens Ag | Traegerfrequenzdrahtfunk-Verteilungsanlage |
DE1940497U (de) | 1966-04-22 | 1966-06-08 | Broads Mfg Company Ltd | Mannlochabdeckung. |
GB1272594A (en) * | 1968-08-09 | 1972-05-03 | Communications Patents Ltd | Improvements in and relating to wired broadcasting systems |
-
1971
- 1971-12-03 GB GB5629971A patent/GB1414127A/en not_active Expired
-
1972
- 1972-11-13 MT MT731A patent/MTP731B/xx unknown
- 1972-11-14 IL IL40843A patent/IL40843A/xx unknown
- 1972-11-14 ZA ZA728071A patent/ZA728071B/xx unknown
- 1972-11-28 CH CH1733372A patent/CH549919A/xx not_active IP Right Cessation
- 1972-11-28 US US310118A patent/US3886456A/en not_active Expired - Lifetime
- 1972-11-28 IT IT54325/72A patent/IT973762B/it active
- 1972-11-29 DE DE2258416A patent/DE2258416C3/de not_active Expired
- 1972-11-29 DE DE2265451A patent/DE2265451C2/de not_active Expired
- 1972-11-30 NL NL7216232A patent/NL7216232A/xx not_active Application Discontinuation
- 1972-12-01 BE BE792215D patent/BE792215A/xx unknown
- 1972-12-01 ES ES409180A patent/ES409180A1/es not_active Expired
- 1972-12-01 FR FR7243474A patent/FR2162236B1/fr not_active Expired
- 1972-12-01 CA CA158,475A patent/CA965526A/en not_active Expired
- 1972-12-04 SE SE7215750A patent/SE383817B/sv unknown
- 1972-12-04 JP JP47120750A patent/JPS4865831A/ja active Pending
Patent Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3244809A (en) * | 1961-03-01 | 1966-04-05 | Pye Ltd | Signal distribution systems |
US3350647A (en) * | 1962-10-25 | 1967-10-31 | Communications Patents Ltd | Wired broadcasting systems and communication cables therefor |
US3277243A (en) * | 1962-12-19 | 1966-10-04 | Burroughs Corp | Telephone adapter |
US3587053A (en) * | 1968-06-10 | 1971-06-22 | Bell Telephone Labor Inc | Audio visual information processing and communication system |
US3691295A (en) * | 1970-03-31 | 1972-09-12 | Ibm | Two-way communication system for video and digital data |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5539635A (en) * | 1994-07-19 | 1996-07-23 | Larson, Jr.; Ernest J. | Radio station program identifier and distribution system |
Also Published As
Publication number | Publication date |
---|---|
CA965526A (en) | 1975-04-01 |
CH549919A (de) | 1974-05-31 |
BE792215A (fr) | 1973-03-30 |
FR2162236A1 (sv) | 1973-07-13 |
DE2265451C2 (de) | 1982-02-18 |
SE383817B (sv) | 1976-03-29 |
DE2258416C3 (de) | 1979-08-09 |
JPS4865831A (sv) | 1973-09-10 |
FR2162236B1 (sv) | 1977-08-26 |
MTP731B (en) | 1973-08-10 |
DE2258416B2 (de) | 1978-12-07 |
ZA728071B (en) | 1973-09-26 |
IL40843A0 (en) | 1973-01-30 |
AU4932372A (en) | 1974-05-30 |
IL40843A (en) | 1975-10-15 |
DE2258416A1 (de) | 1973-06-07 |
NL7216232A (sv) | 1973-06-05 |
GB1414127A (en) | 1975-11-19 |
ES409180A1 (es) | 1976-01-01 |
IT973762B (it) | 1974-06-10 |
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